Lane conditions encountered by a bowler vary significantly. In addition to large variations among different lanes due to age, condition and type of surface, the same lane can vary in surface condition over the course of a game or tournament as a result of its usage. The condition and surface of a lane affects the dynamics of ball travel down the lane and accordingly can cause variation in the path of the ball despite efforts of the bowler to maintain a consistent roll.
Experienced bowlers can control the trajectory of the ball and accordingly are able to adjust to some degree for different lane conditions. Even with such adjustments, however, variations in the condition and surface of the lane across the width and along the length of the lane still can place inconsistencies and variations in ball travel which are unpredictable and detrimental to the player. Accordingly, it is desirable and advantageous to provide a ball which, to the greatest extent possible, provides a consistent roll, minimizes roll variations due to lane surface conditions, thus maximizing the control of the bowler over the ball and providing predictable, consistent characteristics for ball travel.
In application Ser. No. 690,510 a weight block which forms the core of a two-piece bowling ball construction was disclosed which has the effect of providing increased consistency of ball roll over a wide range of lane conditions.
That invention utilized an internal weight block of novel design to provide a substantially increased rotational inertia while conforming with guidelines established for bowling balls by the American Bowling Congress and Women's International Bowling Congress. A bowling ball utilizing the invention provided increased angular momentum to minimize the roll effects of the lane surface while maintaining a weight eccentricity of less than three ounces after drilling when tested according to ABC/WIBC guidelines and maintaining a total ball weight of no more than sixteen pounds.